Engine scavenging system



Nov. 19, 1935.

R. SCHNEIDER ENGINE SCAVENGING SYSTEM Filed Nov; 12, 1930 2 Sheets-Sheet 1 Patented Nov. 19, 1935 PATENT OFFICE ENGINE SCAYENGING SYSTEM Rudolph Schneider, St. Louis, Mo., assignor to Buseh-Slllzer Bros.,-Diesel Engine Company, St. Louis, Mo., a corporation of Missouri Application November 12, 1030, Serial No. 495,012

2 Claims.

The invention relates to multi-cylinder combustion engines, more especially two-cycle injection engines, the object being simplification of the engine and particularly its air supply system,

greater compactness, and improvement in its general structural and operating efllciency as engine cylinders arranged in a straight row as customary, and each comprising a cylinder proper marked 2, and a liner 3 associated therewith to form the usual water jacket space between them. The cylinder head l, though not so showmwill be understood to be supplied with the usual valve mechanismappropriate to thetype of engine on which .the invention isemployed. Each liner 3 is formed with a semi-circular set of exhaust port slots 5 opening to the exhaust manifold 6 also ascustomary in Z-cycle engines, and with a similar set of airport slots I, both sets being uncovered or opened by the piston towardthe end of its working stroke. Reverse flow through the air ports is prevented by check valve mechanism which is shown according to the design of patent September 30, 1924, No. 1,510,143, in which a vertical series of pivoted plates or louvres 8, contained in a suitable box or frame, swing inwardly automatically under the effect 01' air flow to the cylinder, but close by their gravity against above the other, thus obtaining adequate flow capacity with the least extent of lateral projection fromthe cylinder wall, and thereby accommodating and promoting the object of this new combination as will presently appear.

Air is supplied through these inlet valves to the cylinders directly from the interior of/a long horizontal blower casing marked 9-40, which according to thisinvention takes .the place and r position of the familiar horizontal air receiver or air manifold commonly employed in two-cycle engines. Such air manifolds, as well known, are large of diameter inorder to minimize air flow resistance and heretofore they have been sup- .65 plied with air through a connectionwith a single rotary blower usually situated at one end of therow of cylinders and being of large dimensions in order to supply all the cylinders and therefore occupying considerable space. The blower of this invention takes the placeof such com- 5 mon air receiver and, as may be observed in the drawings; requires but little more space on the I engine than was formerly occupied by the air receiver alone. The body part 9 of the blower casing is bolted directly to the engine cylinder 10 structure, and the other part I0 is bolted to the first, the bolts being omitted from tie, drawings for convenience of illustration. The casing may be built up of more than two parts if desired and may have such internal configuration as is re- 15 quired for the type of air impeller or rotor that is used. It extends the full length of the row of cylinders it serves and is secured to them in a. position well above the crankcase enclosure as indicated in Fig. 1, so that the latter and the 201 parts therein are readily accessible beneath it. Its interior space is open laterally to all of the air inlet valves 8, which are in fact located withceiver which it displaces. In the case in hand the impeller means is of the Roots blower type with 35 its rotor elements axially elongated as'stated but divided in two sections, arranged end to end and together constituting a single blower. The two mating rotors on the left hand side of Fig. 3, marked I2 and I3 respectively, constitute one -sec-' 'tion of the impeller system and the-two rotors at the right hand, marked II and 15 are theother; rotors l2 and It being co-axial with each other and I3 and I 5 being also cc-axial; they could be on the same shafts. Each rotor in the present 45 case is mounted oil-independent bearings of its own at the ends of the casing and at the middle on a dividing wall It, which appears in Figures 2 and 3,.and each rotor couple draws in atmos- .pheric air through inlet i1 and delivers it into 50 the long horizontal chamber II which is a common delivery cha her or passage for both couples common also to all of the inlet valves 8 and en- "gine cylinders. This chamber II is formed bythe space between the impeller system and interior V partitions II and th ylinder structure, and its capacity-is great eno gh togive some smoothin i and a still greater degree .of uniformity can obviously be obtained by dividing the impeller system into a greater number of longitudinal sections or couples, no two of which coincide in pressure effect. But two sections angularly dis-' placed as stated and delivering to the common air chamber I 8 are found to be adequate for all ordinary purposes.

The impeller means can 'be driven in any ap propriate way, for instance rotor couple iZ-il' is driven by a spur gear couple I! and sprocket chain or geared belt 20 from one end of the crankshaft and the other couple is driven by similar spur gear couple ii and sprocket chain 22 from the opposite end of the crankshaft. By locating the axis of the upper rotors closer to the engine cylinders than the lower rotor the sprocket chains havea more nearly vertical position and the vertical height of the blower casing is correspondingly though slightly shortened.

4 It will be apparent from the description above given that the principle of the invention comprises the organization of the blower mechanism in a long horizontal housing or casing, directly on the row of engine cylinders in place of the ordinary air receiver, and preferably divided in longitudinal sections-of which the rotors are angularly displaced, and deliver to the horizontal a'ir chamber which is common to inore than one engine cylinder; and within thisprlnciple that the apparatus may take various forms different from that herein shown=for illustration of the invention.

The following is claimed:

1. The improvement in multi-cylinder, twocycie, injection type engines which consists in the combination with a row of upright water-jacketed i twiaimwumatmt I, h

engine cylinders, each of the fuel injection type, and each having a piston-controlled cylinder port for admitting scavenging air thereto independently of fuel, and a non-return valve governing said port, of a horizontal casing structure longitudinally substantially co-extensive with the length of said row and attached to the cylinder jacket thereof above and below the level of said air ports, said casing containing an air-impeller chamber .and a pulsation-absorbing chamber in 10 parallel relation to each other, said pulsationabsorbing chamber extending horizontally and substantially continuously for the full length of said casing between said impeller chamber and the jacket wall of the cylinders-and said impeller chamber housing a plurality of rotors of relatively short radius and elongated axial dimension, said rotors delivering scavenging air through said air chamber. to said air valves, and means for driving the rotors at velocities adapted for 20 air-scavenging purposes. 7

2. The improvement in multi-cylinder twocycle injection engines which consists in the combination with a row of upright water-jacketed engine cylinders, each of the fuel injection type 25 and each having a piston-controlled cylinder port for admitting scavenging air independently of fuel thereto and a non-retum valve governing said port, of a horizontal casing structure longitudinally substantially co-extensive with the length of said row and attached to the cylinder jacket thereof above and below said air ports, said casing containing an air-impeller chamber 1 and a pulsation-absorbing chamber in parallel relation to each other, said pulsation-absorbing chamber extending horizontally and substantially continuously for the full length of said-casing between said impeller chamber and the jacket wall of the cylinders, and said impeller chamber 'housing'a plurality of pairs of rotors of relatively short radius and elongated axial dimension, delivering scavenging air through said air chamber to said air valves, said pairs of rotors being in alignment and angularly displaced relatively to each other, and means for driving the rotors at velocities adapted for air scavenging purposes.

I RUDOLPH SCHNEHDER. 

